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Can the decay rate of ^(32)P be changed by mechanic motion?

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Science china Chemistry 2009年第5期52卷 690-692页

作者： DING YouQian, SUN HongQing, YANG ZhiHong, LIANG XiaoHu, WANG XiaoRong, ZHANG ShengDong & CUI AnZhi Department of Radiochemistry, china Institute of Atomic Energy, beijing 102413, china Department of Radiochemistry China Institute of Atomic Energy Beijing 102413 China

The influence of mechanic motion on the decay rate of 32P was studied by means of liquid scintillation counting (LSC). The results indicate that, on the Northern Hemisphere, the half life of 32P in anticlockwise circular centrifuge rotation (radius 10 cm, 4000 r/min) equals the one in natural conditions within 0.6 percent uncertainty.

关键词： circular rotation 32P decay rate

NONTRIVIAL PERIODIC SOLUTIONS OF A SEMILINEAR WAVE EQUATION WITHOUT ASSUMPTION OF MONOTONICITY

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Systems Science and Mathematical Sciences 1992年第3期5卷 193-204页

作者： LI Shujie (Institute of Mathematics,Academia Sinica,beijing 100080,china) 中科院数学所北京

In references,some authors have succeeded in obtaining existence re-sults of the superlinear wave equation without the assumption of monotonicity forthe nonlinear *** this paper,we present existence results for this p... 详细信息

关键词： Periodic solution superlinear wave equation critical point

SYNTHESIS AND POLYMERIZATION OF TRI(2-PYRIDYL)METHYL METHACRYLATE

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Chinese Journal of Polymer Science 1999年第3期17卷 295-298页

作者： Chuan-fu Chen Yong-hong Yang Fu Xi Institute of Chemistry, Chinese Academy of Sciences, beijing 100080, china Chinese Acad Sci Inst Chem Beijing 100080 Peoples R China

A novel methacrylate monomer with bulky side group, tri(2-pyridyl)methyl methacrylate (Tr2PyMA), was synthesized and polymerized. The polymer obtained by radical polymerization exhibits high isotactic tacticity.

关键词： optical activity tri(2-pyridyl)methyl methacrylate

A tetrahedral data model for unstructured data management

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Science china(Information Sciences) 2010年第8期53卷 1497-1510页

作者： LI Wei & LANG Bo State Key Laboratory of Software Development Environment, Beihang University, beijing 100191, china 1. State Key Laboratory of Software Development Environment Beihang University Beijing 100191 China

This paper proposes a tetrahedral data model for unstructured data management. The model defines the four components of unstructured data including: basic attributes, semantic characteristics, low-level features and raw data on its four facets, and the relations between these components. The internal implementation structure of the model and the data query language are designed and briefly introduced. This model provides a unified, integrated and associated description for different kinds of unstructured data, and supports intelligent data services such as associated retrieval and data mining. An example is given to demonstrate how to use the model for describing and manipulating data from a sample video base.

关键词： unstructured data data model query language associated retrieval intelligent services

GIS conceptual Data Model

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Geo-Spatial Information Science 2002年第3期5卷 19-25页

作者： XIAO Lebin ZHONG Ershun LIU Jiyuan SONG Guanfuassociate researcher,Institute of Geographic Sciences and Natural Resources,Chinese Academy of Sciences,3 Datun Road,Anwai,beijing 100101,china. Institute of Geographic Sciences and Natural Resources Chinese Academy of Science

In order to set up a conceptual data model that reflects the real world as accurately as possible,this paper firstly reviews and analyzes the disadvantages of previous conceptual data models used by traditional GIS in simulating geographic space,gives a new explanation to geographic space and analyzes its various essential ***,this paper proposes several detailed key points for designing a new type of GIS data model and gives a simple holistic GIS data model.

关键词： topological relation layer geographic space holistic data model

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自抗扰控制在火电厂主汽温控制中的应用

系统仿真学报 2005年第1期17卷 241-244页

作者：黄焕袍武利强高峰韩京清林永君北京国电智深控制技术有限公司北京100080 中国科学院数学与系统科学研究院系统科学所北京100085 华北电力大学仿真与过程控制研究所保定071003

针对火电厂过热汽温控制系统的大滞后、大惯性以及动态特性随工况变化的不确定性等特点,本文提出了ADRC过热汽温控制方案。该方案采用导前温度信号作为辅助反馈信号,构成串级ADRC-PID／ADRC双回路控制系统。在电厂过程仿真平台STAR-90... 详细信息

针对火电厂过热汽温控制系统的大滞后、大惯性以及动态特性随工况变化的不确定性等特点,本文提出了ADRC过热汽温控制方案。该方案采用导前温度信号作为辅助反馈信号,构成串级ADRC-PID／ADRC双回路控制系统。在电厂过程仿真平台STAR-90上的实验结果表明,用这种方法建立的过热汽温控制系统,具有较好的控制品质和较强的自适应能力。

关键词：过热汽温控制 STAR-90仿真平台非线性跟踪微分器扩张状态观测器自抗扰控制器

Quasiperiodic Solutions for Nonlinear Differential Equations of Second Order with Symmetry

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Acta Mathematica Sinica,English Series 1994年第3期10卷 231-242页

作者： Liu Bin Department of Mathematics Peking University beijing,100871 china You Jiangong Department of Mathematics Nanjing University Nanjing,210008 china 1. Department of Mathematics Peking University 100871 Beijing China 2. Department of Mathematics Nanjing University 210008 Nanjing China

In this paper,we study the existence of quasi-periodic solutions and the bound- edness of solutions for a wide class nonlinear differential equations of second *** the KAM theorem of reversible systems and the theory of transformations,we obtain the existence of quasi-periodic solutions and the boundedness of solutions under some reasonable conditions.

关键词： Th Quasiperiodic Solutions for Nonlinear Differential Equations of Second Order with Symmetry Math

Cloning of a down-regulated gene encoding small GTP binding protein in hybrid wheat

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Progress in Natural Science:Materials International 2005年第7期15卷 621-626页

作者： YAO Yingyin, NI Zhongfu, CHEN Rongmin, WU Limin and SUN Qixin (Department of Plant Genetic & Breeding, State Key Laboratory for Agro-biotechnology, china Agricultural University, beijing 100094, china) Department of Plant Genetic & Breeding State Key Laboratory for Agro-biotechnology China Agricultural University Beijing 100094 China

Previous studies showed that differential gene expression between wheat hybrids and their parents was responsible for the heterosis. To provide an insight into the molecular basis of wheat heterosis, one cDNA, designated TaRab, was identified from the cDNA library of wheat seedling leaves. The sequence comparison in GenBank revealed that TaRab is homologous to a group of genes encoding Rab-GTP binding protein. Semi-quantitative RT-PCR analysis indicated that TaRab was expressed in all plant tissues examined, but at slightly higher level in leaves. Further analysis exhibited that TaRab displayed lower expression in hybrid than in its patents in both roots and leaves, which was in agreement with the original results of suppression subtractive hybridization. TaRab was located on chromosome 7B and C-7DS5-0.36 by in silico mapping. The relationship between differential expression of TaRab and the molecular basis of wheat heterosis was also discussed.

关键词： wheat Rab protein gene expression heterosis.

Statistical study on the spatial - temporal distribution features of the arctic sea ice extent

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Acta Oceanologica Sinica 1990年第3期9卷 373-387页

作者： Wang Xiaolan, Fan Zhongxiu,Peng Gongbing and Zhou Enji Hohai University, Nanjing,china Institute of Geography,Academia Sinica,beijing,china

On the basis of the arctic monthly mean sea ice extent data set during 1953-1984, the arctic region is divided into eight subregions,and the analyses of empirical orthogonal functions, power spectrum and maximum entropy spectrum are made to indentify the major spatial and temporal features of the sea ice fluctuations within 32-year period. And then, a brief appropriate physical explanation is tentatively suggested. The results show that both seasonal and non-seasonal variations of the sea ice extent are remarkable, and iis mean annual peripheral positions as well as their interannu-al shifting amplitudes are quite different among all subregions. These features are primarily affected by solar radiation, o-cean circulation, sea surface temperature and maritime-continental contrast, while the non-seasonal variations are most possibly affected by the cosmic-geophysical factors such as earth pole shife, earth rotation oscillation and solar activity.

关键词： temporal distribution features of the arctic sea ice extent Statistical study on the spatial